CN111468074A - Acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere and preparation method thereof - Google Patents

Abstract

A preparation method of acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microspheres comprises the following steps of mixing humic acid, hydroxypropyl β -cyclodextrin and a complex containing acrylamide and aluminum sulfate in water, adding N-N-methylene bisacrylamide and potassium persulfate to react at 40-60 ℃, adding span S-80, Tween T-20 and liquid paraffin, stirring at a high speed of 40-60 ℃ to emulsify for 30-60 minutes, reducing the stirring speed after emulsification is completed, heating to 65-75 ℃ to react for 20-40 minutes, adding sodium bisulfite to continue to react for 4-6 hours to obtain an acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Description

Acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere and preparation method thereof

Technical Field

The invention relates to the technical field of sewage treatment, and particularly relates to a preparation method of an acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microsphere.

Background

At present, the discharge of industrial wastewater containing a large amount of highly toxic organic and inorganic anionic pollutants causes serious environmental pollution, and the worldwide attention is drawn. As the most important substance in industrial products, synthetic organic dyes are widely applied to the industries of textile, printing and dyeing, papermaking and the like, and the generated wastewater usually has the characteristics of large water quantity, large water quality change, most of anionic pollutants, higher chemical oxygen demand and poorer biochemical property. Even if the concentration of the dye in the wastewater is very low, the dye still has very high chroma, chemical oxygen demand and lower visible light transmittance and visibility. More serious is the presence of aromatic ring structures in most dye molecules. The aromatic ring has good light and heat stability, is difficult to degrade by organisms, has carcinogenic, Kazaki and mutagenic effects, and can seriously threaten human health and marine organisms. Therefore, it is of great importance to develop effective technical means for removing organic dyes from wastewater before it is discharged.

The invention takes aluminum sulfate, acrylamide, humic acid, hydroxypropyl β -cyclodextrin and the like as main raw materials, synthesizes acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere by an emulsification crosslinking method, and achieves the adsorption effect on anionic pollutants in water by the electric attraction of the cavity of hydroxypropyl β -cyclodextrin in the microsphere and the positive charges carried by aluminum ions, thereby realizing the purification of water and protecting the environment.

Disclosure of Invention

Technically, the key points of the invention are that firstly, the invention uses aluminum ions with three positive charges to ensure that the prepared acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere has enough positive charges so as to have strong enough adsorption effect on anionic pollutants in water and realize adsorption removal of the anionic pollutants, secondly, the invention uses hydroxypropyl β -cyclodextrin in the prepared acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere, the hydroxypropyl β -cyclodextrin has a special truncated conical molecular structure and the hydrophobic characteristic of an external hydrophilic inner cavity, so that the hydroxypropyl β -cyclodextrin can form an effect with various organic and inorganic molecules through Van der Waals force, hydrophobic interaction force, matching effect between main and object molecules and the like, and the unique cavity structure can form a wrapping compound with molecules with proper sizes, and the aluminum ions have good adsorption effect on the anionic pollutants in the wastewater, thereby effectively removing the anionic pollutants in the wastewater.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a preparation method of acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microspheres comprises the following steps:

step 1, dissolving humic acid and sodium hydroxide in a water solvent, adjusting the pH value to 6-8, heating in a water bath to 45-55 ℃ to obtain a humic acid water solution, namely a system 1;

step 2, adding hydroxypropyl β -cyclodextrin into a water solvent, and stirring to disperse the hydroxypropyl β -cyclodextrin to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving acrylamide and aluminum sulfate in a water solvent to obtain a solution of an acrylamide and aluminum complex, namely a system 3;

step 4, uniformly mixing span (S-80), tween (T-20) and liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to raise the temperature to 40-60 ℃, adding N-N-methylene bisacrylamide and potassium persulfate, and stirring the mixture at a constant temperature of 40-60 ℃ and a high speed for reaction for 10 minutes;

step 6, quickly dropwise adding the system 4 into a three-neck flask, stirring at a constant temperature of 40-60 ℃ at a high speed, and emulsifying for 30-60 minutes;

step 7, after emulsification is finished, reducing the stirring speed, heating to 65-75 ℃, and reacting for 20-40 minutes;

step 8, adding sodium bisulfite, stirring at constant temperature, reacting for 4-6 hours, centrifuging the obtained product, pouring out an upper oil phase, and washing and purifying the lower precipitate for multiple times by using ethyl acetate, absolute ethyl alcohol and distilled water in sequence;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Preferably, the mass ratio of the humic acid, the hydroxypropyl β -cyclodextrin, the acrylamide, the aluminum sulfate, the span (S-80), the Tween (T-20), the N-N-methylene bisacrylamide, the potassium persulfate and the sodium bisulfite is (1.0-2.0), (0.5-1.5), (1.0-2.0), (2.0-4.0), (1.0-2.0), (0.2-0.8), (0.5-1.2), (0.5-1.5) and the volume ratio of the solvent water to the liquid paraffin in the fourth step is 1 (1-5).

Preferably, in the step 1, the solvent is water, and the reaction temperature is 45-55 ℃.

Preferably, in the step 1, the amount of sodium hydroxide is 1 mol/L, and the amount is 3-5 ml.

Preferably, in step 2, the solvent is water.

Preferably, in step 3, the solvent is water.

Preferably, in the step 5, stirring is carried out at a constant temperature of 40-60 ℃, and the reaction time is 10-20 min.

Preferably, in the step 6, the constant-temperature high-speed stirring speed is 4000-8000 rpm, and the reaction temperature is 40-60 ℃.

Preferably, in the step 6, the emulsifying time is 30-60 min.

Preferably, in the step 7, the reaction temperature is 65-75 ℃, and the reaction time is 20-40 min.

Preferably, in the step 8, the reaction temperature is 65-75 ℃, and the reaction time is 4-6 h.

The acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere prepared by the preparation method is a gray black powder product.

Compared with the prior art, the invention has the following beneficial technical effects:

according to the invention, in the preparation process of the acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere, the coordination effect of acrylamide and aluminum ions and the introduction of acrylamide and aluminum ions with positive charges into the hydroxypropyl β -cyclodextrin microsphere are utilized, and the adsorption effect on anionic pollutants in water is achieved by utilizing the electric attraction of the positive charges carried by the aluminum ions.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

Example one

Step 1, dissolving 1.0g of humic acid and 3ml of sodium hydroxide in 10ml of water solvent, adjusting the pH value to 6-8, heating in a water bath to 45 ℃ to obtain a humic acid water solution, namely a system 1;

step 2, adding 0.5g of hydroxypropyl β -cyclodextrin into 10ml of water solvent, and stirring to disperse the mixture to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving 1.0g of acrylamide and 2.0g of aluminum sulfate in 20ml of water solvent to obtain acrylamide and aluminum complex solution, namely a system 3;

step 4, uniformly mixing 1.0g of span (S-80), 0.2g of Tween (T-20) and 125ml of liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to 40 ℃, adding 0.5g of N-N-methylene bisacrylamide and 0.5g of potassium persulfate, and stirring the mixture at a constant temperature of 40 ℃ and a high speed for reaction for 10 min;

step 6, quickly dripping the system 4 into a three-neck flask, keeping the temperature at 40 ℃, stirring at 4000rpm at a high speed, and emulsifying for 300 min;

step 7, after emulsification is finished, reducing the stirring speed, heating to 65-75 ℃, and reacting for 20 min;

step 8, adding 0.5g of sodium bisulfite, stirring at constant temperature, reacting for 4 hours, centrifuging the obtained product, pouring out the upper oil phase, and washing and purifying the lower precipitate with ethyl acetate, absolute ethyl alcohol and distilled water for multiple times;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Example two

Step 1, dissolving 1.4g of humic acid and 5ml of sodium hydroxide in 13ml of water solvent, adjusting the pH value to 6-8, heating in a water bath to 55 ℃ to obtain a humic acid water solution, namely a system 1;

step 2, adding 1.5g of hydroxypropyl β -cyclodextrin into 15ml of water solvent, and stirring to disperse the mixture to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving 2.0g of acrylamide and 4.0g of aluminum sulfate in 30ml of water solvent to obtain acrylamide and aluminum complex solution, namely a system 3;

step 4, uniformly mixing 2.0g of span (S-80), 0.8g of Tween (T-20) and 150ml of liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to 60 ℃, adding 1.2g of N-N-methylene bisacrylamide and 1.5g of potassium persulfate, and stirring the mixture at a constant temperature of 60 ℃ and a high speed for reaction for 10 min;

step 6, quickly dripping the system 4 into a three-neck flask, keeping the temperature at 60 ℃, stirring at 8000rpm at a high speed, and emulsifying for 60 min;

step 7, after emulsification is finished, reducing the stirring speed, heating to 75 ℃, and reacting for 40 min;

step 8, adding 1.5g of sodium bisulfite, stirring at constant temperature, reacting for 6 hours, centrifuging the obtained product, pouring out the upper oil phase, and washing and purifying the lower precipitate with ethyl acetate, absolute ethyl alcohol and distilled water for multiple times;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Example three

Step 1, dissolving 2.0g of humic acid and 4ml of sodium hydroxide in 15ml of water solvent, adjusting the pH value to 6-8, heating in a water bath to 50 ℃ to obtain a humic acid water solution, namely a system 1;

step 2, adding 1.0g of hydroxypropyl β -cyclodextrin into 10ml of water solvent, and stirring to disperse the mixture to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving 1.5g of acrylamide and 3.0g of aluminum sulfate in 20ml of water solvent to obtain acrylamide and aluminum complex solution, namely a system 3;

step 4, uniformly mixing 1.5g of span (S-80), 0.4g of Tween (T-20) and 180ml of liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to 50 ℃, adding 0.9g of N-N-methylene bisacrylamide and 1.2g of potassium persulfate, and stirring the mixture at a constant temperature of 50 ℃ and a high speed for reaction for 10 min;

step 6, quickly dripping the system 4 into a three-neck flask, keeping the temperature at 50 ℃, stirring at 6000rpm at a high speed, and emulsifying for 45 min;

step 7, after emulsification is finished, reducing the stirring speed, raising the temperature to 70 ℃, and reacting for 30 min;

step 8, adding 1.0g of sodium bisulfite, stirring at constant temperature, reacting for 5 hours, centrifuging the obtained product, pouring out the upper oil phase, and washing and purifying the lower precipitate with ethyl acetate, absolute ethyl alcohol and distilled water for multiple times;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Example four

Step 1, dissolving 1.2g of humic acid and 4.5ml of sodium hydroxide in 12ml of water solvent, adjusting the pH value to 6-8, heating in a water bath to 48 ℃ to obtain a humic acid water solution, namely a system 1;

step 2, adding 1.3g of hydroxypropyl β -cyclodextrin into 16ml of water solvent, and stirring to disperse the mixture to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving 1.3g of acrylamide and 2.6g of aluminum sulfate in 28ml of water solvent to obtain acrylamide and aluminum complex solution, namely a system 3;

step 4, uniformly mixing 1.8g of span (S-80), 0.3g of Tween (T-20) and 70ml of liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to 55 ℃, adding 0.9g of N-N-methylene bisacrylamide and 0.6g of potassium persulfate, and stirring the mixture at a constant temperature of 54 ℃ and a high speed for reaction for 10 min;

step 6, quickly dropwise adding the system 4 into a three-neck flask, keeping the temperature at 44 ℃, stirring at a high speed of 5000rpm, and emulsifying for 40 min;

step 7, after emulsification is finished, reducing the stirring speed, heating to 67 ℃, and reacting for 35 min;

step 8, adding 1.5g of sodium bisulfite, stirring at constant temperature, reacting for 4.5h, centrifuging the obtained product, pouring out an upper oil phase, and washing and purifying the lower precipitate with ethyl acetate, absolute ethyl alcohol and distilled water for multiple times;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Example five

Step 1, dissolving 1.8g of humic acid and 3.5ml of sodium hydroxide in 18ml of aqueous solvent, adjusting the pH value to 6-8, heating in a water bath to 53 ℃ to obtain a humic acid aqueous solution, namely a system 1;

step 2, adding 0.6g of hydroxypropyl β -cyclodextrin into 7ml of water solvent, and stirring to disperse the mixture to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving 1.8g of acrylamide and 3.6g of aluminum sulfate in 22ml of water solvent to obtain acrylamide and aluminum complex solution, namely a system 3;

step 4, uniformly mixing 1.2g of span (S-80), 0.7g of Tween (T-20) and 120ml of liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to 58 ℃, adding 1.1g of N-N-methylene bisacrylamide and 0.6g of potassium persulfate, and stirring the mixture at a constant temperature of 42 ℃ and a high speed for reaction for 10 min;

step 6, quickly dropwise adding the system 4 into a three-neck flask, keeping the temperature at 42 ℃, stirring at 7000rpm at a high speed, and emulsifying for 55 min;

step 7, after emulsification is finished, reducing the stirring speed, raising the temperature to 73 ℃, and reacting for 36 min;

step 8, adding 0.7g of sodium bisulfite, stirring at constant temperature, reacting for 4.2h, centrifuging the obtained product, pouring out the upper oil phase, and washing and purifying the lower precipitate with ethyl acetate, absolute ethyl alcohol and distilled water for multiple times;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Example six

Step 1, dissolving 1.6g of humic acid and 4.2ml of sodium hydroxide in 18ml of aqueous solvent, adjusting the pH value to 6-8, heating in a water bath to 46 ℃ to obtain a humic acid aqueous solution, namely a system 1;

step 2, adding 1.4g of hydroxypropyl β -cyclodextrin into 17ml of water solvent, and stirring to disperse the mixture to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving 1.6g of acrylamide and 2.2g of aluminum sulfate in 15ml of water solvent to obtain an acrylamide and aluminum complex solution, namely a system 3;

step 4, uniformly mixing 1.7g of span (S-80), 0.3g of Tween (T-20) and 150ml of liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the systems 1, 2 and 3 into a three-neck flask, heating and stirring the mixture to 58 ℃, adding 0.6g of N-N-methylene bisacrylamide and 1.4g of potassium persulfate, and stirring the mixture at a constant temperature of 58 ℃ and a high speed for reaction for 10 min;

step 6, quickly dropwise adding the system 4 into a three-neck flask, keeping the temperature at 47 ℃, stirring at a high speed of 5500rpm, and emulsifying for 55 min;

step 7, after emulsification is finished, reducing the stirring speed, heating to 67 ℃, and reacting for 56 min;

step 8, adding 1.3g of sodium bisulfite, stirring at constant temperature, reacting for 5.4h, centrifuging the obtained product, pouring out an upper oil phase, and washing and purifying the lower precipitate with ethyl acetate, absolute ethyl alcohol and distilled water for multiple times;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

Taking the samples prepared in the embodiment, examining the application effects of the samples, preparing solutions containing four anionic dyes with the concentration of 100 mg/L respectively, and using the solutions as an adsorbent to remove the anionic dyes, the test results show that the adsorption amounts of the acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microsphere materials prepared in the sixth embodiment of the invention to the dyes are 353.7, 365.2, 303.9 and 397.1mg/g respectively.

Comparative example 1

Referring to the sixth example, the difference between the sixth example and the sixth example is that in the step 2, hydroxypropyl β -cyclodextrin is replaced by β -cyclodextrin with equal mass.

In comparative example 1, other types of β -cyclodextrin having a hydrophobic cavity structure were used, and the products prepared by the comparison were irregular in structure, less abundant in voids, and reduced in adsorption capacity, because β -cyclodextrin had poor solubility in water, resulting in non-uniform reaction system and resulting in irregular structure of the products.

Comparative example No. two

Referring to example six, this example differs from example six in that in step 3, acrylamide is replaced with an equal amount of acrylic acid. The rest raw materials and processes are completely the same as the sixth embodiment.

In comparative example 2, other types of vinyl monomer acrylic acid were used, and the adsorption capacity of the product prepared by comparison to anions was significantly reduced. First, this is because the complex formed by acrylic acid and aluminum is not a chelate complex and thus the structure is unstable, and the amount of positively charged aluminum ions introduced into the final product is reduced, thereby reducing the adsorption capacity for anionic contaminants. Secondly, acrylic acid, without amino groups, generally exhibits negative charges in water, greatly impairing the positive charges of the product.

Comparative example No. three

Referring to example six, this example differs from example six in that step 3 is omitted, i.e. no acrylamide and aluminum complex solution is added. The rest raw materials and processes are completely the same as the sixth embodiment.

In comparative example 3, no acrylamide and aluminum complex solution was added, and the adsorption capacity of the product prepared by comparison to anions was significantly reduced. The product prepared by the invention can adsorb anions in water mainly through the action of the electric attraction between the positive electricity carried by the aluminum ions in the complex and the anions.

Comparative example No. four

Referring to the sixth embodiment, the difference between the sixth embodiment and the sixth embodiment is that in the step 5, the reaction time is replaced by 5min and 20min from 10 min. The rest raw materials and processes are completely the same as the sixth embodiment.

In the comparative example 4, the constant-temperature high-speed stirring reaction time under the reaction condition of 40-60 ℃ is replaced, and the adsorption performance of the prepared product to anions is obviously reduced. The possible reasons for the analysis are: if the time is too short, the stirring is insufficient, the system is not uniform, and when the step 6 is carried out, namely the oil phase is added, the reactant in the water phase in the water-in-oil type emulsion is not uniformly distributed and can not be carried out according to the designed reaction, so that the product components and the structure are irregular, and the adsorption force is reduced; if the time is too long, the degree of the cross-linking polymerization reaction in the water phase is larger, so that the hydrophobicity and lipophilicity of the intermediate product are increased, when the step 6 is carried out, namely the oil phase is added, the reactant in the system is extracted into the oil phase to continue the cross-linking polymerization, and resin rather than microspheres is formed, so that the product is not easy to grind and crush, the specific surface area is reduced, and the adsorption force is reduced.

Claims (8)

1. A preparation method of acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microspheres is characterized by comprising the following steps:

mixing a humic acid aqueous solution, a hydroxypropyl β -cyclodextrin aqueous dispersion and a complex aqueous solution containing acrylamide and aluminum sulfate, and adding N-N-methylene bisacrylamide and potassium persulfate to react at 40-60 ℃;

adding span S-80, Tween T-20 and liquid paraffin into the system, stirring at a high speed of 40-60 ℃, and emulsifying for 30-60 minutes; after emulsification is finished, reducing the stirring speed, and heating to 65-75 ℃ for reaction for 20-40 minutes;

and adding sodium bisulfite, continuously reacting for 4-6 hours, centrifuging, taking the lower layer of precipitate, separating and purifying to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

2. The method of claim 1, wherein the acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microspheres are prepared by an emulsion crosslinking method.

3. The method of claim 1, wherein the mass ratio of humic acid, hydroxypropyl β -cyclodextrin, acrylamide, aluminum sulfate, span S-80, Tween T-20, N-N-methylene bisacrylamide, potassium persulfate and sodium bisulfite is (1.0-2.0), (0.5-1.5), (1.0-2.0), (2.0-4.0), (1.0-2.0), (0.2-0.8), (0.5-1.2), (0.5-1.5) and the volume ratio of the total amount of water in the system to the liquid paraffin is (1-5).

4. The method according to claim 1, wherein the humic acid aqueous solution is obtained by dissolving humic acid and sodium hydroxide in a water solvent, adjusting the pH value to 6-8, and heating to 45-55 ℃ for reaction.

5. The method according to claim 4, wherein the humic acid-containing aqueous solution with the pH value of 6-8, the hydroxypropyl β -cyclodextrin aqueous dispersion and the acrylamide-aluminum sulfate-containing complex aqueous solution are mixed, and then N-N-methylene bisacrylamide and potassium persulfate are added at 40-60 ℃ for reaction for 10-20 min.

6. The method according to claim 1, wherein the span S-80, the Tween T-20 and the liquid paraffin are added, and then the mixture is stirred at a high speed of 4000-8000 rpm at a temperature of 40-60 ℃ for 30-60 min.

7. The method of claim 1, comprising the steps of:

step 1, dissolving humic acid and sodium hydroxide in a water solvent, adjusting the pH value to 6-8, heating in a water bath to 45-55 ℃ to obtain a humic acid water solution, namely a system 1;

step 2, adding hydroxypropyl β -cyclodextrin into a water solvent, and stirring to disperse the hydroxypropyl β -cyclodextrin to obtain a hydroxypropyl β -cyclodextrin dispersion system, namely a system 2;

step 3, dissolving acrylamide and aluminum sulfate in a water solvent to obtain a solution of an acrylamide and aluminum complex, namely a system 3;

step 4, uniformly mixing the span S-80, the Tween T-20 and the liquid paraffin to obtain a mixed system, namely a system 4;

step 5, sequentially adding the system 1, the system 2 and the system 3 into a three-neck flask, heating to 40-60 ℃ under heating and stirring, adding N-N-methylene bisacrylamide and potassium persulfate, and carrying out constant-temperature high-speed stirring reaction at 40-60 ℃ for 10 minutes;

step 6, quickly dropwise adding the system 4 into a three-neck flask, stirring at a constant temperature of 40-60 ℃ at a high speed, and emulsifying for 30-60 minutes;

step 7, after emulsification is finished, reducing the stirring speed, heating to 65-75 ℃, and reacting for 20-40 minutes;

step 8, adding sodium bisulfite, stirring at constant temperature, reacting for 4-6 hours, centrifuging the obtained product, pouring out an upper oil phase, and washing and purifying the lower precipitate for multiple times by using ethyl acetate, absolute ethyl alcohol and distilled water in sequence;

and 9, drying the product purified in the step 8 in a vacuum drying oven to constant weight, and grinding and crushing to obtain an acrylamide and aluminum complex/hydroxypropyl β -cyclodextrin microsphere crude product.

8. Acrylic acid and aluminum complex/hydroxypropyl β -cyclodextrin microspheres prepared by the method of any one of claims 1-7.